I have used this award system for 13 years, and the kids really value it.
Children each have a small grid of 25 squares on their desks (made on the computer by the teacher). Squares are stamped when children are working quietly on a task, producing excellent work, doing homework, bringing a diary, consistently following class rules, doing extra jobs or being helpful, i.e. positive behaviours. Children also give them to each other for positive reasons at ‘warm fuzzy time’. I get them to write the person’s name and a reason on a slip of paper which is posted in a box. I then read them all out. When a student gets a grid filled, s/he gets a certificate, i.e. 25 Warm Fuzzies (which the children create) and, at certain times, a prize.
Then they aim for the next award, which is 50, 75, 100, 125, etc. I stress that it isn’t a race to get the most, but only a personal aim. The kids enjoy it, and it promotes positive behaviours and relationships, and they feel special when they receive them from others.